Penetration of cephradine and cefazolin into ulcers of patients suffering from peripheral arterial circulatory insufficiency.

11 patients with peripheral arterial circulatory insufficiency with ulcers on the big toe or on the heel were given 1 g of cephradine intravenously (i.v.) and later 1 g of cefazolin i.v., two cephalosporins with different degrees of protein binding. Antibiotic concentrations were followed in serum and wound secretions after the injections. The peripheral circulatory state of the patients and the degree of protein binding of the cephalosporins used seemed to be of minor importance for the concentrations of the antibiotics in the ulcers, i.e. the infectious focus, compared to local factors such as the bacterial flora of the ulcers. In-vitro studies with bacterial strains isolated from the ulcers of 2 of the patients indicated that beta-lactamases from gram-negative bacteria might be at least part of the explanation for the low concentrations in wound secretion of one or other of the agents used in 4 out of the 11 patients.